US Patent 7237433 Hybrid tire pressure monitoring system

A tire pressure monitoring system for a vehicle having a plurality of inflatable tires includes a plurality of rotation sensors that generate rotation signals based on a rotation of each of the tires and a pressure sensor that is responsive to a pressure within one of the tires and that generates a pressure signal based on the pressure. A control module receives the pulse signals and the pressure signal and that detects a low pressure condition of at least one of the tires based on the pressure signal and the pulse signals.